In this instructable, I show you how to make a little aquaponic system using a solar pump.

Aquaponics is born from the union of two different techniques, aquaculture, which is the breeding of aquatic animals like fish; and hydroponics, which is the cultivation of plants without soil, only with water.

When we combine these two techniques in aquaponic, we create a symbiotic ecosystem, where the fish waste is the nutrients of the plants; and the plants protect the water from the fish.

In the process, also act some bacteria that transform the waste of the fish into nutrients for plants.

Step 1: Materials and Tools

See below the materials and tools that you will need:

Materials:

· Fish tank

· Stones, plants, etc. (to decorate the aquarium)

· Flowerpot / container for plants (I used an old planter)

· Expanded clay balls (you can buy them here)

· Solar water pump (Like this)

· Hose and tubes

Also, you will need hot silicone, flanges, a PET bottle, plastic plug, two component glue / sealer and two component putty (type this)

Tools:

· Cutter

· Hot silicone gun

· Pliers

Step 2: Started

First, and if you use a planter like me, it will cover the holes it brings. For this I use pieces of the PET bottle, a little larger than the hole to be covered.

We will start making some cuts with the cutter on both sides of the hole, so that the glue adheres well.

Inside the planter, I pasted the pieces of bottle with the silicone / hot glue. It does not need to be perfect, since its function is to make the basis for the glue / sealer of two components, which is what will seal the hole.

Then we turn it over, and we have the holes covered, and with a flange of a few millimeters. These flanges will be filled with the two component glue / sealer to leave the waterproof planter. Read the instructions of the glue to make the mixture, know the drying time, etc. (I use a cardboard, I make two strips as similar as possible of both components and mix them until it is homogeneous)

Step 3: Siphon

For the correct oxygenation of the plant’s roots, and all system in general, I make a bell siphon to fill and empty the planter (or container for the plants that you have chosen).

We will use two tubes of different diameter to make it and the plastic cap to seal it. Of the tubes, the smaller diameter has to fit comfortably into the larger diameter and also be longer. The largest diameter pipe will be the water column that the container for the plants will have, so it should be between 1 and 2 cm shorter than the height of the container (to avoid overflowing the water).

We will start for the larger diameter tube, and to do so, we will make some notches in one of the two ends so that water can enter the siphon. This notched end will be the bottom of the siphon.

We will continue making a hole, the same size as the smaller diameter tube, more or less in the center of the planter. We will make some small cuts around the hole, on both sides of the planter, so that we can better stand putty and glue.

We will introduce the smaller diameter tube in the hole and we will make it protrude 2 cm outside the container. Through the inside of the container, we will fix the tube with hot glue.

Seal and finish fixing the tube, on the outside of the planter, with two-component putty.

Once the putty has dried, we will place the largest tube inside the container and fix it with hot glue.

In the photo you can see that I covered the tube with a plastic with holes, do not pay attention to it, I did it to carry out tests. This tube has to be sealed, with the plastic plug, so that the siphon works and the water fills the container and empties periodically. I used a plug of a 5l water jug, and I stuck it with hot glue, but you can use anything that suits you, as long as the tube is well sealed.

Until here, we have the part of the assembly half done, now it is only necessary to fill with the balls of clay the container of the plants, place the water pump and the solar panel, decorate and fill the fish tank.

Step 4: Solar Water Pump

Now we will put the water pump in the fish tank and we will connect the hose. Ideally, it would be placed as far as possible from the drain of the planter’s siphon, in order to ensure that all the water is removed. We will use one of the tubes that the pump brings, as an adapter between the pump and the hose.

At this point, we will place the stones at the bottom of the fish tank and bury the tube and the pump. We will use some stones to keep the pump half a centimeter from the bottom (more or less).

We will also use to put some decorative plant (or whatever you want to put in the fish tank).

We will fill the planter with the expanded clay balls. It will also be time to test the siphon filling the water container, which in turn, will help us to clean the clay balls (we will make the water discharges in another container that is not the fish tank). Then, we will place the planter on top of the tank in its final position

We will make holes in the edge of the planter to hold the hose of the pump with flanges.

We will fix the solar panel in the same way, making holes in the edge of the planter, with flanges and taking advantage of the fixing holes that the panel brings.

To give the inclination to the panel, we can use some wood, piece of plastic or whatever you have on hand, I used a plastic cover that also serves to put the connection of the pump with the panel and the leftover cables.

We finish the assembly by placing the heatsink that brings the pump to the end of the hose (above the planter), so that the water does not come out.

We will also make a last hole, this time in the upper part of the planter as a drain in case the siphon gets stuck.

Step 5: Star Up

Now, we will have everything ready to start with aquaponic. It is very important to remove the chlorine from the water that we use to fill the fish tank, and whenever we have to add it, we will take this point into consideration. If we do not remove the chlorine from the water, the colonies of bacteria that are so important in the system will not form.

To get the chlorine out of the water, you can use one of these chlorideless products, or let the water stand in a container for a few days so that the chlorine evaporates.

We start by placing some plants in the planter and leave the system running a week or two before incorporating the fish.

Finally, and to avoid excessive evaporation of water, I put a polycarbonate sheet over the part of the fish tank that was discovered.